#
# top.uni.aps.anl.gov:/home/www/beamtime-requests/req00231.txt
# UNICAT Member Beam Time Request  #231

# created Mon Dec 03 11:05:04 CST 2001
#
beamline:
	33ID

collaboration:
	No

collaborator+Pete:
	on

contact:
	gabrielle.long@nist.gov

days:
	2

description:
	Waspaloy is a nickel base super-alloy used in aircraft engines.  When this alloy is placed in service, it is subjected to long-term exposure at high temperatures, which can cause the reinforcing gamma prime precipitate population to fluctuate and thus affect the alloy's structural integrity. The population fluctuates as a result of coarsening, dissolution or re-precipitation.  In earlier research, samples were exposed to 1200 F for times ranging from 0 to 12626 hours, and have been characterized using impedance spectroscopy, microhardness measurements, x-ray diffraction and quantitative stereology. The results indicate that the material properties vary with exposure time.  Since microstructure and properties are closely related, it is reasonable to expect that the distribution, shape and size of the precipitates are also changing as a function of exposure time. Selective quantitative stereology data suggest that this is the case, but a statistically valid determination of the sizes and size distributions of the gamma-prime phases is still not available.  We propose to measure USAXS from 9 samples of Waspaloy, starting with a baseline sample, and including the full range of exposures up to 12626 hours to follow the development of precipitates. Knowing the volume fractions of primary and secondary gamma prime precipitates will make it possible to predict the electrical and mechanical properties of these materials as a function of in-service exposure to elevated temperatures.

equipment+required:
	UNICAT USAXS

experiment:
	Distribution of primary and secondary gamma-prime precipitates in Waspaloy as a function of high temperature exposure

foreign+nationals:
	

hazards:
	none

minimumdays:
	2

name:
	Gabrielle Long

new+request:
	on

nonmembers:
	Rosario Gerhardt, Georgia Institute of Technology

unacceptable+dates:
	January is not possible.
	Best dates are between March 11 - 17.


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